i290 Prof. Doebereiner oil his 7iew Experiments. 



causing alcoliol, placed in contact with it, to attract oxygen 

 gas, and to become converted into acetic acid and water; 

 and that this property is hkewise possessed by the oxidized 

 sulphuret of platinum, prepared by treating a solution of that 

 metal with sidphui'etted hydrogen, and exposing in a dry 

 state the sulphuret formed by that means, to the action of at- 

 mosphei'ic air for some weeks. In this very remarkable 

 ])i-ocess, 1 atom ( = 46) of alcohol combines with 4 atoms 

 ( = 4x8 = 32) of oxygen, and forms with it 1 atom ( = 51) of 

 acetic acid, and 3 atoms ( = 3 X 9 =27) of water ; that is to say, 

 equal volumes of the vapour of alcohol and oxygen gas, be- 

 come equal volumes of acetic acid and aqueous vapour ; for 

 1 atom of water is requisite to the isolated existence of acetic 

 acid. The respective proportions in which acetic acid and 

 water appear in this case, are exactly the same as those which 

 they bear to each other in crystallized sugar of lead, and also 

 in the subacetate of copper; the quantity of water in acetate 

 of soda is exactly double that which is contained in each of 

 the former acetates. 



After having finished my experiments on this process of 

 the formation of acetic acid, I took the opportunity of ascer- 

 taining the relations of the two above-named })re})arations of 

 platinum to different elastic fluids. The results of the expe- 

 riments instituted for that purpose are interesting; for I found, 



1. That neither oxygen nor carbonic acid gas was absorbed 

 by the protoxide, or by the oxidized sulphuret of platinum ; 

 but that those substances absorbed every inilammable gas. 



2, That 100 grains of protoxide of ])latinum absorb from 

 15 to 20 cubic inches of hydrogen gas, during which absorp- 

 tion so much caloric is evolved, that the protoxide becomes 

 ignited, and the hydrogen burns v.'ith detonation, if it had 

 been previously mixed with oxygen or with atmospheric air. 



The preparation of platinum, charged with hydrogen, has 

 the property of greedily attracting as much oxygen gas as is 

 requisite for the saturation of the hj'drogen it contains. If 

 atmospheric air, therefore, be suffered to enter the tube con- 

 taining it, it instantly deprives it of its oxygen, and even forms 

 ammonia with a portion of the residual nitrogen, if there be 

 not sufficient oxygen present for its saturation. By this agency 

 the oxide of platinum is reduced, and thei-eby loses its re- 

 markable property of disposing alcohol to become acetic acid, 

 and also that of condensing hydrogen gas ; but, what is very 

 remarkable, it retains the property of determining the latter 

 substance to the state in v,hich it combines with oxygen gas, 

 and becomes water ; and so much heat is evolved during tliis 

 combination, that if the hydrogen, gas be mixed with pure 



oxygen, 



I 



